Triethyl phosphonoacetate → 3,5-Dimethyl-1-(carbethoxymethylene)cyclohexane

Participants

Reaction Conditions

Reaction Steps

85 g of dry toluene are added to a round flask which is fitted with a stirrer, thermometer, dropping funnel and reflux condenser. Under a nitrogen atmosphere there are now introduced 17.2 g of sodium in small portions and the mixture is heated to boiling. After dissolution of the sodium (after about 3 hours), the mixture is cooled to 20° C. and there is slowly added dropwise thereto (during about 11/2 hours) a mixture of 219 g of ethyl diethylphosphonoacetate, 95 g of 3,5-dimethyl-cyclohexanone and 220 g of dry toluene. The temperature is held between 25° and 30° C. The mixture is stirred at this temperature for a further 2 days and thereupon poured on to 400 g of ice, extracted with toluene, washed neutral and concentrated. The residue is distilled over a Widmer column and thus yields 110 g of ethyl 3,5-dimethyl-cyclohexylideneacetate.

Provenance & Evidence